In underground mining excavations a water emulsion having a pressure on an order of 36 MPa is used for supplying combined cutters-loaders. Central supply stations are located in the vicinity of the shaft at a considerable distance from the coal working area and they supply the working medium simultaneously to several working places. But great distances lead to considerable losses and pressure drops for working medium supplied with hoses. For this reason pipes for supply of combined cutters-loaders must be used.
The utility model Ru 36 249 shows a high-pressure pipeline consisting of articulated segments. At the end of each segment there is, on one side, a ball end-piece with a through duct and a nut with rear thrust flange. On the opposite end, there is an externally threaded flange, which on the side of connected adjacent segment, has a seat accommodating a seal in contact with the spherical surface of the adjacent segment.
High-pressure pipeline according to this system has many drawbacks and inconveniences. In the case of an angular location of the connected segments and particularly in the area of curvatures and arcs, the cross section area of the pipeline is considerably reduced and in consequence, the resistance of flow of the working medium which is supplied to the combined cutters-loaders is considerably increased.